© 2014 Valerie Dionne

Galileo’s Starry Night by Lucy Devlin

On March 18, Professor Elizabeth McGrath and the Colby College Space Club led an out of this world event at Colby’s observatory.  The night was clear and perfect for stargazing even with just the naked eyes; the approximately ten of us gathered however had the added bonus of telescopes for even better viewing. Two free-standing telescopes were set up and initially focused on the moons of Jupiter and the Orion nebula. Jupiter looked simply like a bright star, visible even without the telescope; however the telescope allowed us to see the four moons (Io, Europa, Ganymede, and Callisto) that Galileo discovered.  The other free standing telescope was focused on the Orion nebula which is part of the Orion constellation. This is a place where new stars are born; the few stars clustered there are recently born stars (recent in astronomical terms) and the cloudy mist surrounding them will be used to make more stars in the future.

StarryNight2After everyone had a chance to get a look through these telescopes, Professor McGrath led us to look through the much larger research telescope. This telescope is permanently set up in a dome, visible when driving by the lower athletic center parking lot, and was just big enough for the ten of us to fit comfortably inside. This telescope was also focused on the moons of Jupiter and although the image itself was no bigger than the one from the free-standing telescope, it was much crisper. Computers were also set up in the dome surrounding the telescope. These can be used to direct the telescope to certain coordinates in the sky or to command the telescope to move to focus on specific planets. There is also a camera attached to the telescope, housed in a container with liquid nitrogen to keep in cool and prevent interference.

Once we had all looked at through this large telescope we headed back outside to continue observing. Professor McGrath moved one of the free-standing telescopes to see the Pleiades, also known as the seven sisters. Interestingly, although to the naked eye there looked to be seven stars through the telescope there are actually only six bright stars.  The name comes from Greek mythology; the seven sisters were daughters of Atlas (titan) and Pleione (sea-nymph) who served as hand-maidens to Artemis (goddess of the hunt). Orion became interested in the sisters and pursued them for seven years until Zeus finally took pity on them and made them stars. The fact Orion is also a constellation eternalizes his pursuit of them.


Professor McGrath also tried to use the telescope to give us a look at the little dipper; however, this constellation was unfortunately mostly blocked by trees. She did tell us a lot about the little dipper though. One of the stars in the handle is actually a double star (two stars very close to each other) and when looked at through a telescope these two stars are also both double stars. On the basin, the top two stars always points to the North Star so is a convenient way to locate the North Star. The North Star is commonly used as a way for people to find their way when they are lost and can also inform an observer of their exact latitude. Basically, you count the hand lengths it takes from the horizon to the star and each hand length is 10 degrees (if four of your hands would fit in that distance than you are at a latitude of 40 degrees). To be more precise, a fist is equal to 5 degrees and a finger (held horizontally) is equal to 1 degree.  During this time we are also fortunate enough to see a shooting star.

After seeing the little dipper, Professor McGrath took the time to teach us about some of the other constellations. She pointed out Canis Major, a group of stars resembling a dog with Sirius, the brightest star in the sky and often referred to as the dog star, serving as his eye. He is apparently following his master, Orion, as they hunt eternally across the sky. Orion was supposedly a hunter who stepped on Scorpius (a scorpion) after failed pursuit of the seven sisters, in particular Merope. The gods felt sorry for him and put him in the sky as a constellations. They also put his dogs in the sky as constellations (Canis Major) as well as several other animals (like Lepus the rabbit or Taurus the bull).  Three stars clustered in a straight line make up Orion’s belt and a few star vertical to this make up his sword. The Orion nebula is part of the sword. Additionally, there is a red star where his head would be and a blue star by his feet; this color difference actually indicates the temperature of the star with red stars being cool and blue stars hotter.

Censorship was not particularly addressed for this event as it was more just a chance to study the sky like Galileo did. We did discuss though how Galileo noticed the craters on the moon through his use of the telescope, which contradicted Aristotle’s theory that the moon was a perfectly heavenly body. Although Galileo was arrested for his heliocentric ideas, this idea about the moon added to the trouble surrounding him. This just drives home the point that censorship exists in the face of evidence; even if there is solid evidence for one way of thinking people may still try to discredit it if it goes against the popular way of thinking.


“Canis Major, the Great Dog.” StarDate Online. McDonald Observatory. Web. 20 Mar. 2014. <http://stardate.org/nightsky/constellations/orion>.

Gibson, Steven. “Pleiades Mythology.” The Pleiades. Arecibo Observatory, n.d. Web. 20 Mar. 2014. <http://www.naic.edu/~gibson/pleiades/pleiades_myth.html>.

“Orion, the Hunter.” StarDate Online. McDonald Observatory. Web. 20 Mar. 2014. <http://stardate.org/nightsky/constellations/orion>.